Use methanol are a backup with slight increases in timing and you’re fine. Using it as a pure performance gain and there’s always a chance something can fail. I typically use it more for the cooling affect, rather than the increase in octane it offers(allowing increase timing adavnce).
VP M-1 floats around $40 for five gallons. I’ll typically run 3:1 meth/water ratio for street cars. Most systems can’t handle much more of a concentration than that without part degredation over time.